The Pathology and Laboratory Support Core is an effective nucleus that supports the various studies of the program project by providing routine and advanced technical preparations, including morphological analysis of cells, tissue and organ preparations. The core provides diagnostic light microscopic evaluation, epifluorescent microscopy of histological sections and immunohistochemical interpretation of human and murine prostatic tissue and prostate cancer bone metastases. In addition, technologically advanced expert assistance in a broad range of methods, including quantitative RT-PCR and tissue in-situ hybridization are available. Program project investigators utilizing animal necropsies also have access to sophisticated techniques, such as transmission electron microscopy and image analysis/morphometry. Facilities available include histology (special stains, frozen, paraffin- and plastic-embedded sections) and immunohistochemistry. A key advantage of the core is that it enables unified characterization and dissemination of a shared set of histologic standards. Key to the study of the tumor-bone-stromal interaction is the ability to isolate relatively pure samples of the tumor and the surrounding stroma. Particularly relevant to our program project is the ability to do so in the primary tumor as well as in bone specimens with metastasis.The pathology core will a) procure fresh prostatic tissue, including: primary tumor, tumor-related stroma, benign epithelium, metastatic bone specimens, and stroma unrelated to tumor from clinical specimens under direct morphologic visualization using laser capture microscopy for molecular analyses; b) serve as the morphology core, providing prostate cancer diagnostic expertise for both clinical specimens and animal models of prostate cancer, maintain frozen section and light microscopic facilities, histochemistry, immunohistochemistry and in situ hybridization microscopic support; and c) provide ample well-characterized, archived pathologic samples for screening of candidate molecules of potential mechanistic importance, validation of cell culture and animal model experimental data anddiscovery of novel biomarkers, including high throughput analysis - tissue microarray. RELEVANCE (See instructions): Core C will continue to provide both diagnostic and molecular analysis of cell and tissue samples from human and animals. This will allow for more comprehensive quality testing with wider variety of advanced methods. Procedures are standardized and quality-controlled, leading to greater technical uniformity and allowing for direct comparisons between projects. Investigators will continue to have ready access to sophisticated techniques such as transmission electron microscopy and image analysis.